Reggie: The Life of Reginald Maudling by Lewis Baston 320pp, Sutton, £25

For a couple of years, I saw Reggie Maudling on almost every Monday morning that the House of Commons met. He was shadow foreign secretary and I, as minister of state at the Foreign Office, "briefed" him about the state of Britain's relations with the rest of the world. Of course, I only told him what Jim Callaghan wanted him to know. And Maudling had no doubt about the limitations of our conversation. But he was too genial either to complain or attempt to trespass on forbidden territory. He sat back in his armchair and listened - occasionally interrupting my diatribe by walking across my office to refill his glass with a mixture of gin and sweet vermouth.

Although he said very little, his rare interventions left me in no doubt about his remarkable ability. Like many big men, he gave the impression of indolence. And perhaps physically he was lazy. But his mind was sharp and clear and he was certainly the intellectual equal of Iain Macleod, his friend and rival, whose rebarbative manner made him seem more incisive. Macleod's political career ended in early death, Maudling's in the half-world of disgrace that returned to blacken his name long after the offences were committed. The third member of the Tory triumvirate that dominated the party 40 years ago was Ted Heath. Although nothing like as talented as the other two, he became prime minister.

For 20 years, Maudling has been remembered for not much more than his relationship with John Poulson - the architect and builder whose corrupt dealings with T Dan Smith, the leader of the Newcastle council, ruined all three men. Reggie, Lewis Baston's life of Maudling, deals with the scandal in unremitting detail. It includes a forensic demolition of the "personal statement" to the House of Commons in which the deposed home secretary attempted to prove his innocence. But the real Maudling rarely shines through the meticulous catalogue of his life and times. He was a man of vision as well as ability - just as solid but far more sparkling than Baston suggests.

Maudling - like Macleod and Enoch Powell - began his real political life as part of the Conservatives' Opposition Secretariat, which was set up under Winston Churchill's leadership but without much enthusiasm from the great man. Maudling was secretary of the group, which wrote the Tories' Industrial Charter, an attempt to move the party into the 20th century by accepting some of the economic prescription (including public ownership) that had been worked out by the Labour government. Maudling told me that, when he drafted a passage on the subject for the leader's conference speech, Churchill told him: "I don't believe a word of it." Nevertheless he read out Maudling's draft to the appreciative, if bemused, party delegates.

Maudling regarded that early achievement in persuasion as evidence of his progressive views on economic policy. He inherited the Plowden Committee's reforms on the management of public expenditure and applied them with vigour, as well as developing what was then the almost revolutionary innovation of government intervention in the economy - including the controversial area of wage determination. Wage control would, he believed, guarantee "expansion without inflation". Much to his credit, he was in constant conflict with Lord Cromer, the free marketeer governor of the Bank of England, and his criticism of his predecessor's "stop-go" policy was rejection of the "stop" element in the equation. His instinct was for economic growth.

The policy failed and, in easily the best part of the biography, Baston attributes Maudling's failure to win the Conservative leadership contest in 1965 to memories of his years at the Treasury. Cromer settled old scores by telling newspapers that "foreign bankers regard Maudling as the architect of our financial misfortunes... if he becomes leader, the effect on the pound will be bad". Heath's victory (by a clear majority of only two votes) was, according to Reggie, a psychological blow from which Maudling never recovered.

The degeneration - both emotional and physical - was accelerated, in Baston's view, by the behaviour of Beryl Maudling. Reggie's wife wanted "the good life and the bright lights" and insisted on taking her husband to parties which he did not enjoy. She is described as "never someone to bake a cake". Politicians - notably Harold Macmillan - have transcended greater marital traumas and survived. Maudling, in truth, did the same.

He became home secretary three years after he lost the leadership and - had he not been voluble in his criticisms of Margaret Thatcher's economic policy - might well have put the Poulson scandal behind him and become foreign secretary in 1979. He never became prime minister. But that is not the only mark of political success.

· Roy Hattersley's The Edwardians: Biography of the Edwardian Age is published by Little, Brown.